Los Angeles, USA. The system has been rigorously tested at the most prestigious universities and laboratories in the U.S., Canada and China. BauGrid, manufactured with high-strength steel wire rods, up to 3/4- inch in diameter, are placed in two layers, and resistance-welded at every intersection using modern proprietary welding techniques and strict quality assurance procedures developed by BauGrid in conjunc- tion with the most prominent concrete researchers around the world. Merdeka PNB-118 consists of a reinforced concrete core structure surrounded by 8 Mega Columns as large as 3200 mm x 4200 mm (10’- 6” x 13’-9”). Two major non-rectangular shaped columns (known as Hammerhead) with an approximate maximum overall dimension of 4400 mm x 7400 mm (14’-6” x 24’-3”) were designed for each end of the minor axis of the core structure. As part of the feasibility study, BauGrid was initially considered for the 8 perimeter Mega Columns. A half-sized mock-up column of 3200 mm Wide x 2060 mm Deep x 2500 mm High (10’-6” W x 6’-9” D x 8’-3” H) was constructed in Singapore (Photos 3 and 4). Multiple cages were assembled with 19 mm (3/4”) diameter BauGrid elements and connected together with BauGrid splices. The mock-up construc- tion team analyzed fabrication, installation, and assembly of the rebar cages. All longitudinal reinforcement consisted of T40 (1.57” diam- eter) high grade rebars.
in concrete as well as yield strain for longitudinal rebars and BauGrid reinforcement closely matching that of the conventional design. Under peak load, the longitudinal rebars were in the plastic state while the BauGrid ties were in elastic state.
Photo 5
The final decision by the construction team was to use BauGrid in the Hammerhead columns at the core as the complexity and congestion of the rebars had to be overcome in order to allow the core walls to be constructed at a faster rate, ahead of the perimeter Mega Columns. Over 570 - T40 (1.57” diam.) longitudinal rebars were pre-assembled in 16 different rebar cages, using various configurations, utilizing 19 mm (3/4”) diameter BauGrid Reinforcement grids (Photo 6).
A comprehensive non- linear finite element analysis for Hammerhead Column was carried out at Seoul National Univer - sity, comparing the con - ventional rebar tie & stir- rup design with BauGrid transverse confinement reinforcement (Photo 5). For both models, Design Load of 313 MN (70,366 Kips) and Peak Load of 690 MN (155,120 Kips) were applied. It was con - cluded that although less cross ties were used in the
Photo 3
BauGrid model, resulting in less rebar congestion, the final results were about the same as original conventional rebar option with tensile strain
Photo 6
BauGrid is produced at qualified and U.S. Certified facilities around the world. During manufacture, the BauGrid steel material and resis- tance welded connections are rigorously tested per ASTM and Bau - Grid’s own proprietary tests based on the findings of its over 30 years of research. Traditional transverse reinforcement represents a small proportion of the volume of reinforcing steel but a very large share of the fabrication
Photo 4
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November 2021 csengineermag.com
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